azurestack: Add a custom rhcos image field for ASH

Add a new field to the install config so users can specify an RHCOS image
to use in their ASH environment. This field is required for ASH, and not
allowed to be used for azure.

data/data/install.openshift.io_installconfigs.yaml

@@ -1342,6 +1342,11 @@ spec:
                     - AzureGermanCloud
                     - AzureStackCloud
                     type: string
+                  clusterOSImage:
+                    description: ClusterOSImage is the url of a storage blob in the
+                      Azure Stack environment containing an RHCOS VHD. This field
+                      is required for Azure Stack and not applicable to Azure.
+                    type: string
                   computeSubnet:
                     description: ComputeSubnet specifies an existing subnet for use
                       by compute nodes

pkg/asset/installconfig/azure/client.go

@@ -26,6 +26,7 @@ type API interface {
 	GetDiskSkus(ctx context.Context, region string) ([]azsku.ResourceSku, error)
 	GetGroup(ctx context.Context, groupName string) (*azres.Group, error)
 	ListResourceIDsByGroup(ctx context.Context, groupName string) ([]string, error)
+	GetStorageEndpointSuffix(ctx context.Context) (string, error)
 }
 
 // Client makes calls to the Azure API.
@@ -94,6 +95,12 @@ func (c *Client) getVirtualNetworksClient(ctx context.Context) (*aznetwork.Virtu
 	return &vnetsClient, nil
 }
 
+// GetStorageEndpointSuffix retrieves the StorageEndpointSuffix from the
+// session environment
+func (c *Client) GetStorageEndpointSuffix(ctx context.Context) (string, error) {
+	return c.ssn.Environment.StorageEndpointSuffix, nil
+}
+
 // getSubnetsClient sets up a new client to retrieve a subnet
 func (c *Client) getSubnetsClient(ctx context.Context) (*aznetwork.SubnetsClient, error) {
 	subnetClient := aznetwork.NewSubnetsClientWithBaseURI(c.ssn.Environment.ResourceManagerEndpoint, c.ssn.Credentials.SubscriptionID)

pkg/asset/installconfig/azure/validation.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"net/url"
 	"sort"
 	"strconv"
 	"strings"
@@ -41,6 +42,13 @@ func Validate(client API, ic *types.InstallConfig) error {
 	allErrs = append(allErrs, validateNetworks(client, ic.Azure, ic.Networking.MachineNetwork, field.NewPath("platform").Child("azure"))...)
 	allErrs = append(allErrs, validateRegion(client, field.NewPath("platform").Child("azure").Child("region"), ic.Azure)...)
 	allErrs = append(allErrs, validateInstanceTypes(client, ic)...)
+	if ic.Azure.CloudName == aztypes.StackCloud && ic.Azure.ClusterOSImage != "" {
+		StorageEndpointSuffix, err := client.GetStorageEndpointSuffix(context.TODO())
+		if err != nil {
+			return err
+		}
+		allErrs = append(allErrs, validateAzureStackClusterOSImage(StorageEndpointSuffix, ic.Azure.ClusterOSImage, field.NewPath("platform").Child("azure"))...)
+	}
 	return allErrs.ToAggregate()
 }
 
@@ -274,6 +282,9 @@ func ValidatePublicDNS(ic *types.InstallConfig, azureDNS *DNSConfig) error {
 func ValidateForProvisioning(client API, ic *types.InstallConfig) error {
 	allErrs := field.ErrorList{}
 	allErrs = append(allErrs, validateResourceGroup(client, field.NewPath("platform").Child("azure"), ic.Azure)...)
+	if ic.Azure.CloudName == aztypes.StackCloud {
+		allErrs = append(allErrs, checkAzureStackClusterOSImageSet(ic.Azure.ClusterOSImage, field.NewPath("platform").Child("azure"))...)
+	}
 	return allErrs.ToAggregate()
 }
 
@@ -319,3 +330,24 @@ func validateResourceGroup(client API, fieldPath *field.Path, platform *aztypes.
 	}
 	return allErrs
 }
+
+func checkAzureStackClusterOSImageSet(ClusterOSImage string, fldPath *field.Path) field.ErrorList {
+	var allErrs field.ErrorList
+	if ClusterOSImage == "" {
+		allErrs = append(allErrs, field.Required(fldPath.Child("clusterOSImage"), "clusterOSImage must be set when installing on Azure Stack"))
+	}
+	return allErrs
+}
+
+func validateAzureStackClusterOSImage(StorageEndpointSuffix string, ClusterOSImage string, fldPath *field.Path) field.ErrorList {
+	var allErrs field.ErrorList
+	imageParsedURL, err := url.Parse(ClusterOSImage)
+	if err != nil {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("clusterOSImage"), ClusterOSImage, fmt.Errorf("clusterOSImage URL is invalid: %w", err).Error()))
+	}
+	// If the URL for the image isn't in the Azure Stack environment we can't use it.
+	if !strings.HasSuffix(imageParsedURL.Host, StorageEndpointSuffix) {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("clusterOSImage"), ClusterOSImage, "clusterOSImage must be in the Azure Stack environment"))
+	}
+	return allErrs
+}

pkg/asset/installconfig/azure/validation_test.go

@@ -376,3 +376,52 @@ func Test_validateResourceGroup(t *testing.T) {
 		})
 	}
 }
+
+func TestCheckAzureStackClusterOSImageSet(t *testing.T) {
+	cases := []struct {
+		ClusterOSImage string
+		err            string
+	}{{
+		ClusterOSImage: "https://storage.test-endpoint.com/rhcos-image",
+		err:            "",
+	}, {
+		ClusterOSImage: "",
+		err:            "^platform.azure.clusterOSImage: Required value: clusterOSImage must be set when installing on Azure Stack$",
+	}}
+	for _, test := range cases {
+		t.Run("", func(t *testing.T) {
+			err := checkAzureStackClusterOSImageSet(test.ClusterOSImage, field.NewPath("platform").Child("azure"))
+			if test.err != "" {
+				assert.Regexp(t, test.err, err.ToAggregate())
+			} else {
+				assert.NoError(t, err.ToAggregate())
+			}
+		})
+	}
+}
+
+func TestValidateAzureStackClusterOSImage(t *testing.T) {
+	cases := []struct {
+		StorageEndpointSuffix string
+		ClusterOSImage        string
+		err                   string
+	}{{
+		StorageEndpointSuffix: "storage.test-endpoint.com",
+		ClusterOSImage:        "https://storage.test-endpoint.com/rhcos-image",
+		err:                   "",
+	}, {
+		StorageEndpointSuffix: "storage.test-endpoint.com",
+		ClusterOSImage:        "https://storage.not-in-the-cluster.com/rhcos-image",
+		err:                   `^platform.azure.clusterOSImage: Invalid value: "https://storage.not-in-the-cluster.com/rhcos-image": clusterOSImage must be in the Azure Stack environment$`,
+	}}
+	for _, test := range cases {
+		t.Run("", func(t *testing.T) {
+			err := validateAzureStackClusterOSImage(test.StorageEndpointSuffix, test.ClusterOSImage, field.NewPath("platform").Child("azure"))
+			if test.err != "" {
+				assert.Regexp(t, test.err, err.ToAggregate())
+			} else {
+				assert.NoError(t, err.ToAggregate())
+			}
+		})
+	}
+}